1. Field of the Invention
The present invention relates to a slide device and electronic equipment, and particularly relates to a slide device and electronic equipment capable of causing a slider or casing to move at a low load.
2. Description of the Related Art
Slider type mobile telephones have become widespread in recent years. A rear surface of a front casing and a front surface of a rear casing of such mobile telephones are connected by a slide device. It is then possible to slide the front casing vertically with respect to the rear casing. An urging mechanism is then typically utilized in order to move the front casing at a low load.
For example: with a mobile telephone as disclosed in Unexamined Japanese Patent Application KOKAI Publication No. 2007-49650, referring to FIGS. 5 and 6 of the literature, a slide member (10) is fitted to a front casing (1) and is coupled so as to be vertically slidable with respect to a rear casing (2). A quadrilateral shaped cam (5) having a pair of left and right angled cam surfaces (4) extending vertically is provided at the rear casing (2). A pair of left and right cam followers (7) is also provided at the slide member (10) so as to be capable of moving in a lateral direction. A spring (8) is dropped in between the pair of cam followers (7). This means that the pair of cam followers (7) sandwich the cam (5) from the left and right so as to press against a pair of cam surfaces (4). When the front casing (1) is slid upwards from a state where the mobile telephone is closed, the pair of cam followers (7) slides over the angled cam surfaces (4) and the spring (8) is stretched out. When the pair of cam followers (7) then travels over the apexes of the angled cam surfaces (4), the pair of cam followers (7) slides upwards due to the force of the spring (8) and the reactive force of the cam surfaces (4) so that the front casing (1) is automatically made to slide upwards. Similarly, when the front casing (1) is slid downwards from a state where the mobile telephone is opened, when the pair of cam followers (7) travels over the apexes of the angled cam surfaces (4), the front casing (1) is automatically slid downwards.
According to the above urging mechanism, the cam followers (7) slide over the same cam surfaces (4) regardless of whether the mobile telephone is opened or closed. This means that the position of the front casing (1) when the cam followers (7) travel over the apexes of the angled cam surface (4) is the same when opening or closing the mobile telephone. Therefore, when the apexes of the cam surfaces (4) are positioned closer to the lower end than to the upper end of the cam (5), the distance that the front casing (1) slides upwards against the force of the spring (8) becomes short and the distance that the front casing (1) automatically slides upwards becomes long in opening the mobile telephone. This means that the operation of opening the mobile telephone becomes easy for the user. On the other hand, however, the distance that the front casing (1) slides downwards against the force of the spring (8) becomes long and the distance that the front casing (1) automatically slides downwards becomes short in closing the mobile telephone. This means that the operation of closing the mobile telephone becomes difficult for the user.
Conversely, when the apexes of the cam surfaces (4) are positioned closer to the upper end than to the lower end of the cam (5), the operation of closing the mobile telephone becomes easy, but the operation of opening becomes difficult.